Expression device for automatic musical instruments.



J; FlALA.

EXPRESSION DEVICE FOR AUTOMATIC MUSICAL INSTRUMENTS. APPLICATION FILED Dec. 1, 1915.

1,178,004. Patented Apr. 4, 1916;

mess 6 am y -Hr -t+ f fivdt THE COLUMBIA PLANSGRAPH (20., WASHINGTON, D. C. v I I ITEI) STATES PATENT OFFICE.

JOSEPH FIALA, OF NEW YORK, N. Y., ASSIGNOR T0 STANDARD PNEUMATIC ACTION COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

EXPRESSION IDEVICE FOR AUTOMATIC MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented Apr. 4, 1916.

Application filed December 7, 1915. Serial N 0. 65,618.

To all whom it may concern:

Be it known that I, JOSEPH FIALA, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a newand useful Expression Device for Automatic Musical Instruments, of which the following is a specification.-

This invention relates to an expression device for automatic musical instruments and is more particularly designed for use in connection with player pianos and piano players. In these types of instruments the operating mechanism commonly comprises a large number of pneumatic devices, each one of which controls a separate note in the instrument. These pneumatics are usually operated upon the suction or exhaust principle, the low pressure of the exhaust being produced by foot -operated bellows. order to prevent frequent changes of pressure due to irregular operation of the bellows, a storage reservoir is commonly provided which'acts as a pneumatic governor for absorbing the irregularities of pressure. In the playing of the instrument it is fre quently desirable to accentuate a given note or series of notes by more vigorous operation of the pumping pedals. The storage reservoir or pneumatic governor however tends to neutralize the effect of the increased speed of operation of the pedals and it thus becomes desirable under these conditions to temporarily shut off the storage reservoir from the wind trunk. Various devices have been heretofore constructed for accomplishing this purpose, and it is the object of my present invention to improve and simplify I the construction of such devices, making them more efiicient in operation and more readily adjustable to varying conditions.

With this general object in view my invention relates to certain arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

A preferred form of my invention is shown in the drawings in which- Figure 1 is a vertical sectional elevation of a storage reservoir having my improved expression device applied thereto, the section being'taken on the line 11 in Fig. 2,

the wind trunk at a point intermediate its ends. The reservoir is constructed in the form of a collapsible bellows having a fixed leaf 14 firmly secured to the wind trunk 10 and having a movable leaf 15 hinged to the fixed leaf. The leaves 14 and 15 are normally forced apart by a spring 16 positioned within the bellows. The reservoir 13 is connected to the wind trunk 10 by a transverse passage 17, the reservoir being otherwise closed.

An expression valve 18 is hinged at 19 to the leaf Hand when closed covers the passage 17 A threaded plunger 20 is mounted to slide transversely through the fixed wall 14 anclis provided at its inner end with a head 21 engaging an extension 22 upon the valve 18. A nut 23 is threaded upon the plunger 20 and is engaged by the free end of a spring 24 secured at 25 to the leaf 14-.

The spring 24 normally presses the plunger 2O inward until the nut 23 engages the outer face of the wall 14:, the plunger being thus made effective to position the valve 18 as shown in Fig. 1. The amount of valve opening may be regulated by turning the nut 23 upon the threaded plunger 20 and the tension of the spring 21 may be adjusted by means of a screw 26 which engages the spring 24 intermediate its ends.

A stop screw 27 may also be provided for limiting the rearward movement of the valve 18. Accurate adjustment of the stop 27 is not commonly necessary as the weight of the valve 18 will cause it to remain in contact with the head 21 of the plunger 20 even if it does not engage the stop 27. The stop may be adjusted, however, by removing the plate 28 provided upon the hinged. lea 5 of the storage reservoir,

Having thus described my invention, the operation thereof willbe evident to those skilled in the art. the valve 18 will. remain open as shown in Fig. 1 and air will flow freely in one direction or the other through the passage 17 to equalize the pressure in the wind trunk 10.

When the foot-operated bellows are suddenly operated at increased speed, thereby producing an abrupt drop of pressure in the wind trunk 10, the excess of pressure in the storage reservoir will cause the valve 18 to close, overcoming the resistance of the spring 24. As soon as this valve is closed the storage reservoir 15 is cut off entirely from the pneumatic system and variations in pressure in the wind trunk will be transmitted direct to the pneumatic actions, providing the desired accentuation. By the provision of the adjusting nut 23 and the adjusting screw 26', I am able to regulate the valve opening and the pressure on the valve entirely from the. outside: of the bellows 13 and without disturbing any of the parts of the mechanism.

Having thus described my invention, what Under normal conditions I claim as new and desire to secure by Letters Patent is: a

An expression device for automatic musical instruments comprising a wind trunk, a bellows connected by a passage through one Wall thereof to said Wind trunk and otherwise closed, a valve in said bellows effective to close said passage upon sudden decrease in pressure in said wind trunk,v a threaded plunger slidable transversely in the wall of said bellows and engaging an JOSEPH FIALA.

Witnesses:

JorrN ALECATO, A. W. JOHNSTON.

Copies of thisv patent may be obtained for five. cents each, by addressing the Commissioner of Patents,

' Washington, 110. 

